From Halopedia, the Halo wiki
The UNSC Verdant Sumerian is a ship in service with the United Nations Space Command Navy. In October of 2558, its shipboard artificial intelligence, Lychus, defected to the Created.
By October 28, 2558; the ship was fitted with the Artificial intelligence Lychus.
By October 28, 2558; the ships AI Lychus defected to the Created.